What is Payment Processing Software?

Payment processing software powers credit and debit card purchases. When customers make a purchase online, they enter their payment and shipping information into a payment gateway. The payment gateway gives that payment information to the payment processor, which then communicates with both the customer’s and merchant’s banks to complete the transaction. The transaction’s success or failure is reported back to the payment gateway and the customer. In a brick-and-mortar store, a customer’s credit or debit card is swiped into a point of sale (POS) system, which communicates with a payment processor to approve or deny the purchase. Many payment processors charge a fee for each transaction based on the size of the purchase. Some payment processors have an embedded payment gateway or POS system to create a seamless experience. Any time a credit or debit transaction is attempted, a payment processor is needed. With the rise of digital wallets, payment processors have expanded their functionality to include digital currency and the transfer of money from a source such as Venmo or PayPal to an e-commerce or brick-and-mortar store. Some can process an e-check or set up recurring payments. Key Benefits of Payment Processing Software Processing payments made by credit, debit, and gift cards as well as digital wallets Creating a seamless experience for customers Determining whether or not payment is valid before fulfilling an order or completing a transaction Communicating with a variety of banks to accept payment from anywhere in the world

Why Use Payment Processing Software?

Security — Payment information is extremely sensitive, so it needs protection. Payment processing software is held to high security standards to protect this sensitive information. Scalability — A small business can use the same payment processor as a large enterprise, with little difference in functionality. Payment processors operate behind the scenes, and companies pay fees to use them. If a small business picks the right payment processor when it starts out, it may never need to change payment processors as their needs increase. Some payment processors handle billing and invoicing, so some internal processes are covered. Flexibility — Most payment processors handle a wide variety of payments. All payment processors process credit and debit cards, but more are accepting payments from digital wallets, cryptocurrencies, and electronic checks. Some facilitate automatic payments to provide consumers and merchants an added convenience of regular payments. The more options provided to the consumer, the more opportunities a merchant has to make a sale, so it’s in a business’ best interest to utilize a payment processor with a variety of features.

Who Uses Payment Processing Software?

E-commerce businesses — E-commerce businesses rely on payment processing software because that is how they receive all payments. Payment processors integrate with the payment gateway an online business uses or the payment processor has its own payment gateway. Some e-commerce platforms have built-in gateways or processors, eliminating the need to choose a specific one.Because payment processors typically charge fees for each transaction, an e-commerce business needs to be mindful of the processor they choose because all their transactions are carried out by the payment processor. Brick-and-mortar businesses — Brick-and-mortar businesses use payment processors to process credit cards and other non-cash payments. Typically, a processor is integrated with the POS system used by the store, but an all-in-one POS system might include a payment processor. Since most shoppers use some kind of card to make purchases, a payment processor is a necessity. Business to business businesses — Every business collects payments in one form or another but businesses that cater to serving other businesses have a unique challenge. Some payment processors are equipped to accept e-checks and lines of credit, and integrate with billing and invoicing software to ensure payments are made and the proper documentation is created. Recurring and automatic payments are useful if a business functions on a subscription model.

Page 5 | Best Payment Processing Software: User Reviews from September 2026

Monto

Monto is the autonomous co-worker that gets you paid by your enterprise customers, end-to-end. Across more than 20,000 customer relationships, it puts a self-learning AI agent on each one, learning the exact workflows of the AP portals your customers use, such as Coupa, Ariba, Tungsten, Tipalti, and 600+ others, and carrying every invoice from your ERP through to payment. For accounts receivable and finance teams, most of the work tied to customer AP portals is manual: logging into each portal, submitting invoices in the format that portal requires, chasing POs, and checking payment statuses across dozens of disconnected systems. Monto takes that end-to-end process off the team's desk, and setting it up doesn't need IT. Best For: Finance and AR teams at mid-market and enterprise B2B companies whose customers require invoicing through AP portals. Billing specialists, collections specialists, AR and credit managers, O2C leads, Controllers, and CFOs dealing with manual portal work, limited visibility and control, and late payments. Just part of what Monto does: - Connects your ERP to every customer AP portal, so invoices move from your system into each portal without manual uploads. - Submits each invoice in the exact, unique format the portal requires, reducing rejections that delay payment. - Tracks POs and payment status automatically across all your customers' portals, in real time. - Deploys dedicated AI agents per customer relationship that learn and adapt to that customer's specific portal requirements over time. - Consolidates everything into one AI-powered dashboard, giving you a single source of truth for invoices, POs, and payment statuses across all portals. Differentiators: Other AR tools automate the parts inside your own system, then hand the portal work back to a person. Monto goes into the portal and does it. Your team sits above the agents and reviews their work rather than doing it, and every review teaches them, so the next round runs with less checking. Monto is the co-worker you didn't have to hire. Awards & Recognition: In G2's Summer 2026 reports, Monto earned 12 badges across Accounts Receivable, Payment Processing, and Payment. Monto was named a G2 Momentum Leader in Accounts Receivable, a High Performer in Accounts Receivable (overall, Mid-Market, and Enterprise), and Easiest To Do Business With and Best Support in Accounts Receivable (overall and Mid-Market). In Payment Processing, Monto was named a High Performer and earned the Best Support award. In the Payment category, Monto was named a High Performer and earned the Best Support award. Last Updated: September 2026

Average Rating: 4.5/5.0

Total Reviews: 53

How Do G2 Users Rate Monto?

Has the product been a good partner in doing business?: 9.6/10 (Category avg: 8.8/10)
Self Service Portal: 9.2/10 (Category avg: 8.6/10)
Level 3: 8.3/10 (Category avg: 7.8/10)
Accounting integration: 9.4/10 (Category avg: 8.4/10)

Who Is the Company Behind Monto?

Seller: Monto
Company Website:
Year Founded: 2021
HQ Location: New York, IL
LinkedIn® Page: www.linkedin.com
121 employees on LinkedIn®

Who Uses This Product?

Who Uses This: Accounts Receivable Specialist
Top Industries: Computer Software, Accounting
Company Size: 43% Large, 36% Medium

What Do G2 Reviewers Say About Monto?

AI-generated summary from verified user reviews

Pros

Users praise Monto for its time-saving capabilities, streamlining invoicing processes and enhancing overall efficiency.
Users find Monto to be easy to use and implement, streamlining their invoicing processes and enhancing efficiency.
Users appreciate the time-saving invoicing capabilities of Monto, enhancing efficiency and improving cash flow significantly.
Users commend the responsive customer support of Monto, appreciating quick assistance whenever needed.
Users highlight the significant efficiency improvements Monto provides, allowing teams to focus on strategic work and collections.

Cons

Users experience connection issues with Monto, finding the process complicated and less helpful for high-touch customer engagement.
Users note the limited availability of PO access, which can hinder the experience for some customers.
Users find the difficult setup for viewing invoices can slow down their experience despite an otherwise user-friendly interface.
Users experience invoicing issues, as viewing multiple invoices can be slow despite an otherwise user-friendly interface.
Users find the process complexity of Monto challenging, especially in managing multiple portal logins effectively.

What Are Recent G2 Reviews of Monto?

"Automated Invoice Uploads That Free Up Our Billing Team"

Rating: 4.0/5.0 stars

— Verified User in Retail

Best Payment Processing Software - Page 5

How Many Payment Processing Software Products Does G2 Track?

Category Stats (Sep 2026)

How Does G2 Rank Payment Processing Software Products?

G2 Grid® for Payment Processing Software

How Do G2 Users Rate Monto?

Who Is the Company Behind Monto?

Who Uses This Product?

What Do G2 Reviewers Say About Monto?

Pros

Cons

What Are Recent G2 Reviews of Monto?

How Do G2 Users Rate Pin Payments?

Who Is the Company Behind Pin Payments?

Who Uses This Product?

What Are Recent G2 Reviews of Pin Payments?

What Are G2 Users Discussing About Pin Payments?

How Do G2 Users Rate TrueLayer?

Who Is the Company Behind TrueLayer?

Who Uses This Product?

What Are Recent G2 Reviews of TrueLayer?

How Do G2 Users Rate 8am ClientPay?

Who Is the Company Behind 8am ClientPay?

Who Uses This Product?

What Are Recent G2 Reviews of 8am ClientPay?

What Are G2 Users Discussing About 8am ClientPay?

How Do G2 Users Rate Simpro?

Who Is the Company Behind Simpro?

Who Uses This Product?

What Do G2 Reviewers Say About Simpro?

Pros

Cons

What Are Recent G2 Reviews of Simpro?

What Are G2 Users Discussing About Simpro?

How Do G2 Users Rate Juspay?

Who Is the Company Behind Juspay?

Who Uses This Product?

What Do G2 Reviewers Say About Juspay?

Pros

Cons

What Are Recent G2 Reviews of Juspay?

What Are G2 Users Discussing About Juspay?

How Do G2 Users Rate Aeropay?

Who Is the Company Behind Aeropay?

Who Uses This Product?

What Do G2 Reviewers Say About Aeropay?

Pros

Cons

What Are Recent G2 Reviews of Aeropay?

How Do G2 Users Rate PDCflow?

Who Is the Company Behind PDCflow?

Who Uses This Product?

What Do G2 Reviewers Say About PDCflow?

Pros

Cons

What Are Recent G2 Reviews of PDCflow?

What Are G2 Users Discussing About PDCflow?

How Do G2 Users Rate Opayo?

Who Is the Company Behind Opayo?

Who Uses This Product?

What Are Recent G2 Reviews of Opayo?

What Are G2 Users Discussing About Opayo?

How Do G2 Users Rate SoFi Tech Solutions?

Who Is the Company Behind SoFi Tech Solutions?

Who Uses This Product?

What Do G2 Reviewers Say About SoFi Tech Solutions?

Pros

Cons

What Are Recent G2 Reviews of SoFi Tech Solutions?

What Are G2 Users Discussing About SoFi Tech Solutions?

How Do G2 Users Rate PayConex?

Who Is the Company Behind PayConex?

Who Uses This Product?

What Are Recent G2 Reviews of PayConex?

How Do G2 Users Rate Benji Pays?

Who Is the Company Behind Benji Pays?

Who Uses This Product?

What Do G2 Reviewers Say About Benji Pays?

Pros

Cons